Despite recent widespread recognition of child depression as a valid and potentially debilitating clinical phenomenon, controversy remains as to the etiology, significance, and prognostic power of depression in childhood. The primary goal of the proposed research is to identify the antecedents and sequelae of depression during the early course of disorder. A particular focus is placed on understanding the rise in depression during adolescence, especially in girls. The model guiding the research posits that family dysfunction in the form of parental depression and lifetime family disruptions fosters the development of maladaptive conceptions of interpersonal relationships and ineffective coping, which create a vulnerability to depression. Stressful circumstances, including the negotiation of normative developmental transitions, are hypothesized to activate this vulnerability, leading to depression during transition periods. Girls are expected to be most sensitive to these processes due to personal characteristics as well as the experience of unique challenges during adolescence. Finally, depression is expected to induce further psychosocial disruption, which increases the likelihood of persistence or recurrence of disorder across adolescence. This proposed multivariate model will be examined using a prospective, multi-informant, multi-method design. Subgroups of depressed, externalizing, and comparison children selected from a community sample will be followed over a period of 2 1/2 years to explore the social-cognitive, affective, interpersonal, and contextual processes underlying onset and recurrence of depression during the early course of disorder. Ultimately, it is anticipated that knowledge from such research can inform the creation of empirically based intervention programs designed to treat childhood-onset depression.